Burner Applications in Ethylene Cracking Furnaces Operating at - PowerPoint PPT Presentation

Ethylene Producers’ Conference (EPC) Burner Applications in Ethylene Cracking Furnaces Operating at Significantly Less Than 90 mg/Nm 3 Presenter: Ryan Roberts Project Engineering Manager Process Burners  ZEECO, INC.

 Introduction  Ultra Low NOx Emissions of less than 90 mg/Nm3 can be difficult in Ethylene Cracking  Typical NOx Reduction Methods Can Lead to Longer Flame Lengths  Longer Flame Lengths Cause: • Flame Rollover to Process Tubes • Flame Impingement on Process Tubes, and Hot Spots • Shorter Run Time Between Decoking • Reduced Ethylene Production  ZEECO, INC.

 Introduction (cont’d)  Zeeco’s GLSF Enhanced-Jet Flat Flame Floor Mounted Burner  Burner entrains unburned fuel next to furnace wall  Mixes inert flue gas products of combustion with unburned fuel gas  Results: • Lower peak flame temperature • Reduced NOx emissions • Reduction in tendency for flame rollover because mixture is kept close to furnace wall  ZEECO, INC.

 Description of Application  (8) New Ethylene cracking furnace train  (7) Twin cell furnaces with: • (64) burners per furnace • Furnace 210-F-1110 to 210-F-1170  (1) Single cell furnace with: • (24) burners • Furnace 210-F-1180  ZEECO, INC.

 Description of Application (cont’d)  Twin Cell Furnaces • (32) Burners per Cell  Single Cell Furnace • (24) Burners  Tubes in Center of Furnace  Burners Fire Up the Furnace Wall  Close Spacing Between Burners  ZEECO, INC.

 Summary Information for Bottom Burners Summary Details for Furnaces 210-F-1110 to 210-F-1170 Number of burners 7 Furnaces x 64 per furnace 2 Cells per furnace (32 per cell) (2 rows × 16 per side) Type of burner GLSF Enhanced Jet Burners complete with internal fuel gas recirculation Type of fuel (gas/oil/dual oil-gas) gas only Location in furnace (roof/floor/side wall) floor Firing orientation (down-firing/upshot/radiant wall /against wall) upshot (against wall) Flame shape (round flame/flat flame) flat flame gas burner assembly Air supply system (natural/forced/induced/balanced/GTE) induced draft fan with natural draft burners Max. available combustion air pressure at burner, mm H2O 13 Ambient temperature (normal), ℃ 16 Relative humidity, % 82% Altitude above sea level, m 674 Flue gas temperature at cross-over ℃ 1115 Maximum Heat Release (Gcal/hr) 1.830 Normal Heat Release (Gcal/hr) 1.530 Minimum Heat Release (Gcal/hr) 0.230 Turndown 7.96 Available Fuel Pressure (MPa(g)) 0.27 Design Excess Air 10% Flame Shape Flat Flame Maximum Predicted Flame Length (m) 6.01 Maximum Predicted Flame Width (m) 0.79  ZEECO, INC.

 Summary Information for Bottom Burners Summary Details for Furnaces 210-F-1180 Number of burners 1 Furnaces x 24 per furnace 1 Cell per furnace (24 per cell) (2 rows × 12 per side) Type of burner GLSF Enhanced Jet Burners complete with internal fuel gas recirculation Type of fuel (gas/oil/dual oil-gas) Gas only Location in furnace (roof/floor/side wall) floor Firing orientation (down-firing/upshot/radiant wall /against wall) Upshot (against wall) Flame shape (round flame/flat flame) flat flame gas burner assembly Air supply system (natural/forced/induced/balanced/GTE) induced draft fan with natural draft burners Max. available combustion air pressure at burner, mm H2O 13 Ambient temperature (normal), ℃ 16 Relative humidity, % 82% Altitude above sea level, m 674 Flue gas temperature at cross-over ℃ 1115 Maximum Heat Release (Gcal/hr) 1.850 Normal Heat Release (Gcal/hr) 1.540 Minimum Heat Release (Gcal/hr) 0.230 Turndown 8.04 Available Fuel Pressure (MPa(g)) 0.27 Design Excess Air 10% Flame Shape Flat Flame Maximum Predicted Flame Length (m) 6.01 Maximum Predicted Flame Width (m) 0.80  ZEECO, INC.

 Comparison to Low Emissions Burners Low Emissions Staged Fuel Burner Zeeco GLSF Enhanced Jet Flat Flame Burner  ZEECO, INC.

 Comparison to Low Emissions Burner (cont’d)  Typical Low Emissions Burner Low Emissions Staged Fuel Burner Zeeco GLSF Enhanced Jet Flat Flame Burner • ~70% of Fuel in Staged Gas Tips • Fires Across the Air Stream at Abrupt Angle • Fast Mixing of Fuel Gas and Combustion Air • Generates Much Higher NOx Emissions  ZEECO, INC.

 Comparison to Low Emissions Burner (cont’d)  Zeeco GLSF Enhanced-Jet Flat Flame Burner Low Emissions Staged Fuel Burner Zeeco GLSF Enhanced Jet Flat Flame Burner • ~70% of Fuel in Staged Gas Tips • Staged Tips Located on Side of Burner Throat • Delayed Mixing of Fuel Gas and Combustion Air • Induces Mixing of Inert Flue Gas Products Into Unburned Fuel • Reduction in NOx Emissions  ZEECO, INC.

 GLSF Enhanced Jet Flat Flame Burner  Staged Ports on Side of Burner Tile Allow: • Fuel Gas to Avoid Passing Directly Over Combustion Air Stream • Delayed Fuel and Air Mixing to Reduce Peak Flame Temperature • Reduction in Peak Flame Temperature to Decrease NOx Emissions • More Fuel and Air Momentum on Furnace Wall to Reduce Potential for Flame Roll Over • Better Control of Flame Width and Length • Uniform Heat Flux Profile in the Middle and Upper Regions of the Burner Flame • Even Heat Transfer and Reduction in Possibility of Tube Hot Spots  ZEECO, INC.

 NOx Reduction Reduction in Peak Flame Temperature = Reduction in NOx Emissions  ZEECO, INC.

 NOx Reduction (cont’d)  2 Types of NOx Reduction Used in Project • Delayed Mixing of Fuel and Combustion Air with Staged Tip Location • Internal Flue Gas Recirculation (IFGR) of Flue Gas Into Staged Fuel Stream  Both Methods Are Used Together to Reduce NOx Emissions without Compromising Flame Shape  Mixture of Inert Flue Gas and Fuel Gas Is Between 15% And 50% Inert  Results in Lower Peak (Adiabatic) Flame Temperature  ZEECO, INC.

 NOx Reduction (cont’d)  Large Amounts of IFGR  Flame Stays Along the Furnace Wall  No Flame Rollover  Uniform Heat Flux Profile  Reduced NOx Emissions  ZEECO, INC.

 Emissions Guarantees Guarantees for NOx, CO, UHC, and Particulate Emissions:  NOx Emissions Will Not Exceed 90 mg/Nm3  CO Emissions Will Not Exceed 30 mg/Nm3  Particulate (PM10) Emissions Will Not Exceed 10 mg/Nm3  UHC Emissions Will Not Exceed 11 mg/Nm3  Burner Noise Level Will Not Exceed 85 dBA at 1 Meter From the Burner  ZEECO, INC.

 Conclusions  (8) New Ethylene Cracking Furnaces Needed to Operate at Less Than 90 mg/Nm3 Nox Emissions  After Retrofit, Closely Mounted Burners Showed No Signs of Flame Interaction or Rollover  Burners Achieved Desired Emissions, and Normally Operate Well Below Guaranteed Levels  Field Measured NOx Emissions Were 35 mg/Nm3 (17 ppmv) to 65 mg/Nm3 (32 ppmv) at Designed Heat Release  ZEECO, INC.

QUESTIONS?  ZEECO, INC.